1. Field of the Invention
The present invention relates to both centrifugal and positive displacement pumps, motors, and similar devices.
2. Description of the Prior Art
The prior art includes a substantial number of centrifugal pumping devices. These are relatively inexpensive compared to their capacity, can run and high speeds, and have numerous other advantages associated with centrifugal pumps. The prior art also includes a substantial number of positive displacement pumping devices. These can be very efficient at slow speeds, and in smaller sizes, and when lower flow rates are required.
In so far as applicant knows, up to the present time, these have been considered to be two different types of pumps, and no one has designed the pump having the advantages of both and the relative disadvantages as between the two of neither. The present invention is such a composite. In addition, its fabricating and manufacturing costs are substantially less than either of a prior art types of pumps of similar capacity and it lasts longer by a substantial margin than prior art centrifugal pumps.